1. Field of the Invention
The present invention pertains to the field of oil reconditioning devices and particularly to oil filters and the associated closure mechanisms.
2. Prior Art
There are a number of oil reconditioning devices known to the prior art. With specific reference to oil reconditioning devices for continuous use in a lubricating oil system, the general approach is to pass contaminated oil into a filter chamber containing filters made of cotton or similar material. After the contaminants are removed, the purified oil is directed out of the device. Prior to leaving the oil reconditioning device, the oil may be subjected to heating in order to vaporize contaminants such as water. A venting or vacuum exhaust system may be attached near the outlet to carry away vaporized impurities.
An important element in the design of oil filtering systems is the need to ensure that oil flows through the filters rather than around them near the filter chamber wall. In oil reconditioning device design, therefore, there is a need to apply downward force on the filters thus compressing them in a manner that causes them not only to press tightly against the interior wall of the housing but to compress them to inhibit "channelling" through the filter. In addition, oil is usually introduced into the filter chamber at a point to force it through the filters. Oil exits the filters through a dispersion plate having small holes or passages and into an evaporation chamber and then out of the device. The oil reconditioning devices in the prior art employ a variety of means to apply downward force to the dispersion plate in an attempt to obtain proper compression of the filters. As a general proposition, the means for forcing the dispersion plate downward involves pressure directed at the perimeter of the plate, or pressure directed at the center or a combination of the two. See U.S. Pat. Nos. 2,110,124 (Fitz Gerald); 2,173,631 (Niedens); 2,206,358 (Koinzan); 2,274,132 (Ehlers); 2,346,042 (Morris); 2,377,988 (Braun); 2,909,284 (Watkins); 3,616,885 (Priest); 3,915,860 (Priest); 4,006,084 (Priest); and 4,338,189 (Johnson). Fins may also be used to apply downward pressure to the dispersion plate, see U.S. Pat. No. 2,206,358 (Koinzan).
While the above described devices have adequate securing means, a more desirable approach is to apply downward pressure on the filters via the dispersion plate at a point between the center and the perimeter. A force applied in this manner will tend to push outwardly as well as downwardly thus providing a tighter fit. The approach, however, can not only result in an increase in the number of components involved thus adding expense as well as weight to the device, but also may interfere with the vaporization process used to remove water and similar contaminants. Also, it is important that the filter compacting apparatus be easy to use because of the need to change filters periodically. Some of the prior art requires a tool to compress the plate against the filter and then turn the plate to lock beneath internal lugs.
It is an object of the present invention to provide an improved oil reconditioning device which provides a filter compacting and positioning system that results in less oil bypassing the filtration process as well as a better means to remove water and other contaminants. A further object is to provide an improved oil reconditioning device that is lighter in weight and less expensive in construction than prior devices. A specific object is to provide an oil reconditioning device that has a filter compacting and positioning means built into the device that can be used in a variety of filtering applications without interfering with the filtering processes. Another specific object is the provision of an improved device in which the filter is easily replaceable without the use of special tools and the like and which a new filter can be compacted without the use of special tools. Other objects will appear from a more detailed description of the invention which follows.